Boeing 417, a Fascinating Footnote of Aviation History

Americans were returning home, and they were bringing with them a desire to spend money on goods and services, as well as the capability to manufacture them. Most aircraft manufacturers took a bullish approach to the impending boost in the economy and wasted no time designing new aircraft. Their designs ranged from small single-engine GA aircraft like the Navion to large transports like the Boeing 417, seen here.

The industry learned many lessons in the surge to churn out warplanes at an unprecedented pace and was well-prepared to hit the ground running. To design and launch a new airplane, manufacturers typically only needed approval from top management—and a customer base willing to purchase the new product.

Boeing took a fresh look at the travel requirements of a postwar populace and identified a need for a smaller airliner to serve regional routes. In 1946, it came up with the 417, an 18,365-pound, twin-engine aircraft designed to carry 20-24 passengers at a speed of 200 mph. While the 417 would never get off the drawing board, it serves as a fascinating footnote of Boeing's history.

Boeing clearly drew inspiration from the 377 Stratocruiser when designing the nose section and tail, and one wonders how much of this was driven by marketing versus engineering. This design might have been chosen to accommodate pressurization, but the square passenger windows suggest the 417 was intended to fly without it. It's possible Boeing wanted to future-proof the airplane to some extent, easing the potential adaptation of pressurization in later versions.

Boeing chose the 800 hp Wright Cyclone C7BA1, essentially the same powerplant as the R-1300 used by the North American T-28 Trojan trainer. 

If this overall design seems familiar, it might be attributable to the similar design of the Douglas DC-5.

The DC-5 featured nearly identical engines, weights, and dimensions as the Boeing, but differed in that 12 examples were actually built and flown, the first flight taking place before WWII in 1939.

The Boeing appeared more advanced than the DC-5, but the performance numbers were nearly an exact match with the exception of the 417’s short-field performance, which was notably optimistic. The 417 was claimed to require only 1,200 feet to clear a 50-foot obstacle and 1,735 feet very impressive performance for its size and weight. 

Proposed performance on the ground was similarly impressive, with features that were said to enable turnaround times of six minutes or less.

Boeing claimed this was achievable through the aircraft's independence from ground equipment. The airstair door enabled boarding without the need for separate stairs, and the height of the cargo hold floor was said to match the height of truck beds, eliminating the need for ramps or hoists. In this diagram, we see the aircraft being refueled with the right engine running as cargo is loaded and passengers begin to board.

Presenting the concept to potential customers like Pan Am was one thing. Boeing also released data and artists' renderings to the media, and it became prominently featured on magazine covers.

Historically, this hasn't been a terribly common move for Boeing's marketing department. However, attempting to garner support and demand from the general public is a tactic they have occasionally employed, as evidenced by the Sonic Cruiser concept. Boeing even ran its own ads in various publications.

Boeing did secure at least one order for the 417 when Empire Airlines ordered three of them to replace their Boeing 247s. In the September 1946 issue of Boeing Magazine, the 417 was said to provide a 57 percent greater break-even load factor than the 247D, promising greater profitability with fewer seats filled.

Just as Boeing was presenting the 417 to customers, Convair was doing the same with its 107, albeit without such a strong marketing and promotional effort.

While both concepts were forward-thinking solutions to shorter, lower-capacity routes, their roles would ultimately be filled with the glut of surplus aircraft from the war effort—namely, the DC-3, which provided similar performance for pennies on the dollar.

As is usually the case in the airline industry, profitability proved to be the top priority, and when it came down to it, those old, cheap taildraggers simply couldn't be beat.